Galson Sciences Ltd - Gas generation and migration
On behalf of Nirex, GSL has conducted a review of mechanisms for Carbon-14 gas generation from intermediate-level waste packages under repository operational and post-closure conditions for the Nirex Phased Geological Repository Concept (PGRC). The review examined possible mechanisms for gaseous Carbon-14 generation from organic wastes and irradiated metals, the associated Carbon-14 inventories, and the treatment of Carbon-14 gas migration through the repository near-field, far-field, and biosphere. Subsequently, for Nirex, GSL conducted a review to compare the treatment of gas generation and migration for assessments of the Nirex PGRC, and the spent fuel and high-level waste disposal concepts in Switzerland and France. The review compared the potential volumes of gas generated by corrosion reactions, organic material degradation, and radiolysis, assumptions about gas migration through the repository near- and far-fields, and the treatment of radioactive gas migration for each concept.